Disaster officials rushed food, medicine and a temporary morgue to the Samoas on Wednesday after a powerful earthquake unleashed a tsunami that flattened villages and swept cars and people out to sea. At least 99 people were killed.

Survivors fled the waves for higher ground on the South Pacific islands after the magnitude 8.0 quake struck at 6:48 a.m. local time Tuesday.

Four tsunami waves 15 to 20 feet high roared ashore on American Samoa about 15 minutes after the quake, reaching up to a mile inland, Mike Reynolds, superintendent of the National Park of American Samoa, was quoted as saying by a parks service spokeswoman.

Military transports carrying medical personnel, food, water, medicines and other supplies were headed to the stricken islands.

"Right now, we're focused on bringing in the assistance for people that have been injured, and for the immediate needs of the tens of thousands of survivors down there," said Federal Emergency Management Agency Administrator Craig Fugate. A Coast Guard C-130 plane loaded with aid and carrying FEMA officials was headed from Hawaii to American Samoa's capital of Pago Pago, where debris had been cleared from runways to allow for emergency planes to land.

AP Photo/Fili SagapoluteleA resident walks past debris in a playground and a tennis park left by the tsuami that struck early Tuesday in Pago Pago, American Samoa. A powerful quake in the South Pacific hurled massive tsunami waves at the shores of Samoa and American Samoa, flattening villages and sweeping cars and people back out to sea while leaving at least 99 dead and dozens missing.

"I cannot tell you exactly what kind of damages we had. We're getting reports just like everyone else that this is a significant impact," he said.

New Zealand's acting Prime Minister Bill English said tents, stretchers, the temporary morgue facilities and a body identification team were sent to Samoa after a "specific request" from local officials, who are "are very concerned about the growing death toll."

The quake was centered about 120 miles south of the islands of Samoa, which has about 220,000 people, and American Samoa, a U.S. territory of 65,000.

Another strong underwater earthquake rocked western Indonesia on Wednesday, less than 24 hours after the Samoan quake, briefly triggering a tsunami alert for countries along the Indian Ocean. The 7.6-magnitude quake toppled buildings, cut power and triggered a landslide on Sumatra island, and at least 75 people were reported killed. Experts said the seismic events were not related.

The Samoan capital, Apia, was virtually deserted by afternoon, with schools and businesses closed. Hours after the waves struck, sirens rang out with another tsunami alert and panicked residents headed for higher ground again, although there was no indication of a new quake.

In Pago Pago, the streets and fields were filled with ocean debris, mud, overturned cars and several boats as a massive cleanup effort stretched into the night. Several buildings in the city — just a few feet above sea level — were flattened. Power was expected to be out in some areas for up to a month.

President Barack Obama has declared a major disaster for American Samoa. Obama said in a statement early Wednesday that he and his wife, Michelle, "will keep those who have lost so much in our thoughts and prayers."

Hampered by power and communications outages, officials in the South Pacific islands struggled to determine damage and casualties.

Hundreds of people bombarded American Samoa's radio stations with requests that they announce the names of their missing loved ones in hopes they could be found. Radio stations responded with announcements urging listeners to contact their families immediately.

Water service has been restored to many villages, but power is still out in most areas. More than 1,000 people spent the night in 15 emergency shelters.

Samoan police commissioner Lilo Maiava told The Associated Press that police had confirmed 63 deaths but devastated areas were still being searched.

At least 30 people were killed on American Samoa, Gov. Togiola Tulafono said, adding that the toll was expected to rise from searches by emergency crews.

"I don't think anybody is going to be spared in this disaster," said Tulafono, who was in Hawaii for a conference. He added that a member of his extended family was among the dead.

Authorities in Tonga, southwest of the Samoas, confirmed at least six dead and four missing, according to English.

Joey Cummings of radio station 93KHJ in Pago Pago told the BBC that he and his colleagues watched from a balcony as a 15-foot tsunami wave struck, and "the air was filled with screams."

He yelled for people to run uphill, "but they just ran down the street away from the wave rather than make a sharp left and up the steep mountain just feet away."

A "river of mud" carried trees, cars, buses and boats past his building, which is practically at sea level, Cummings told the BBC.

Some people searched for trapped survivors, he said, but others looted stores. Bodies were stacked in the back of pickup trucks, he added.

Alex Godinet, chief of staff for American Samoa's congressional delegate, said his "whole house and everything was shaking." When he went to the nearby village of Leone, the tsunami wave had already struck and receded.

"People, elders were trying to crawl all over the place, crawl up to higher place, higher areas," he told NBC's "Today" show.

All 65 employees at the National Park of American Samoa were accounted for, although at least one of them lost a home, said Holly Bundock, spokeswoman for the National Park Service's Pacific West Region in Oakland, Calif. The park service employs 13 permanent workers and between 30 and 50 volunteers, depending on the time of year.

The Australian Department of Foreign Affairs said three Australians were among the dead. The British Foreign Office said one Briton was missing and presumed dead.

"So much has gone. So many people are gone," he told reporters on board. "I'm so shocked, so saddened by all the loss."

Malielegaoi said his own village of Lepa was destroyed.

"Thankfully, the alarm sounded on the radio and gave people time to climb to higher ground," he said. "But not everyone escaped."

Tulafono said that because the closeness of the community in American Samoa, "each and every family is going to be affected by someone who's lost their life." He spoke to reporters in Hawaii before boarding the Coast Guard C-130 plane with the FEMA officials.

A New Zealand P3 Orion maritime surveillance airplane had reached the region Wednesday and had searched for survivors off the coast, he said.

The Samoa Red Cross estimated that 15,000 people were affected by the tsunami.

New Zealander Graeme Ansell said the Samoan beach village of Sau Sau Beach Fale was leveled.

"It was very quick. The whole village has been wiped out," Ansell told New Zealand's National Radio from a hill near Apia. "There's not a building standing. We've all clambered up hills, and one of our party has a broken leg. There will be people in a great lot of need 'round here."

Residents of both Samoa and American Samoa said they were shaken awake by Tuesday's quake, which lasted two to three minutes and was centered about 20 miles (30 kilometers) below the ocean floor. It was followed by at least three large aftershocks of at least 5.6 magnitude.

The quake came Tuesday morning for the Samoas, which lie just east of the international dateline. For Asia-Pacific countries on the other side of the line, it was already Wednesday.

American Samoa's dominant industry — tuna canning — was also affected. Chicken of the Sea's packing plant was forced to close, although the facility wasn't damaged, the San Diego-based company said.

The effects of the tsunami could be felt nearly 5,000 miles away (7,500 kilometers) on a Japanese island, though there were no reports of damage or injuries there.

U.S. officials said strong currents and dangerous waves were forecast from California to Washington state. No major flooding was expected, however.

While the earthquake and tsunami were big, they were not on the same scale of the 2004 Indian Ocean tsunami, said Brian Atwater of the U.S. Geological Survey in Seattle. That tsunami killed more than 230,000 in a dozen countries across Asia.

Although the quakes in the Samoas and Indonesia struck within 24 hours of each other, experts said there was no link between them.

"When you look at that, it's like, 'Oh something's going on there.' But researchers are convinced that because quakes are essentially a random process that they're not related," said Don Blakeman, an analyst for the U.S.-based National Earthquake Information Center.

Various factors explain why the Samoa earthquake caused a massive tsunami and the Indonesia quake, with a magnitude of 7.6, did not.

The difference in magnitude was one factor, Blakeman said. "It also has to do with the depth of earthquakes. The Samoan one was very shallow. The Sumatran one, I think, was about 80 kilometers (49 miles)."